Runoff Generation and Soil Erosion at Different Age of Acacia Plantation in Hoa Binh Province, Vietnam

Abstract

To determine the characteristics of runoff generation and soil erosion at the different ages of Acacia plantation in Luong Son headwater of Vietnam, four plots (15m 2 plot -1 ) were set up. Of those, two plots were at up-hill and down-hill in 1-year-old and two plots in 5-years-old Acacia plantation. Soil erosion and runoff were monitored during rainy season from April to September 2018. The main findings include: (1) Runoff coefficient at Acacia 1-year-old down and up ranged from 0.36% -0.46% with the average 0.41%. Acacia 5-years-old, down and up was 0.35% -0.39%, averaged 0.37%. It shows the slightly diffences between the locations of two years due to the different ground cover but not statistically significant different; (2). Soil erosion in Acacia-1 and Acacia-5 year old were 21.84 and 14.20 ton/ha/6months, respectively. The data for soil erosion was statistically significant different between two ages of Acacia plantation. Soil erosion at the study site was very high within strong erosion base on TCVN5299: 2009; (3) Both runoff and soil erosion had strong relationship with precipitation (R 2 range from 0.52-0.85, with P-value = 0.00). This result suggests that more concerning and applying suitable management for reducing the negative impact of Acacia plantation at the headwater of Vietnam is necessary.

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